package com.java.study.common.utils;

import org.w3c.dom.Node;
import org.w3c.dom.NodeList;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.transform.OutputKeys;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;
import java.io.ByteArrayInputStream;
import java.io.InputStream;
import java.io.StringWriter;
import java.util.*;
import java.util.stream.Collectors;

/**
 * 微信支付工具类，xml转map,map转xml，生成签名
 */
public class WXPayUtil {

	/**
	 * XML格式字符串转换为Map
	 */
	public static Map<String, String> xmlToMap(String strXML) throws Exception {
		try {
			Map<String, String> data = new HashMap<String, String>();
			DocumentBuilderFactory documentBuilderFactory = DocumentBuilderFactory.newInstance();
			DocumentBuilder documentBuilder = documentBuilderFactory.newDocumentBuilder();
			InputStream stream = new ByteArrayInputStream(strXML.getBytes("UTF-8"));
			org.w3c.dom.Document doc = documentBuilder.parse(stream);
			doc.getDocumentElement().normalize();
			NodeList nodeList = doc.getDocumentElement().getChildNodes();
			for (int idx = 0; idx < nodeList.getLength(); ++idx) {
				Node node = nodeList.item(idx);
				if (node.getNodeType() == Node.ELEMENT_NODE) {
					org.w3c.dom.Element element = (org.w3c.dom.Element) node;
					data.put(element.getNodeName(), element.getTextContent());
				}
			}
			try {
				stream.close();
			} catch (Exception ex) {
				// do nothing
			}
			return data;
		} catch (Exception ex) {
			throw ex;
		}

	}

	/**
	 * 将Map转换为XML格式的字符串
	 */
	public static String mapToXml(Map<String, String> data) throws Exception {
		DocumentBuilderFactory documentBuilderFactory = DocumentBuilderFactory.newInstance();
		DocumentBuilder documentBuilder = documentBuilderFactory.newDocumentBuilder();
		org.w3c.dom.Document document = documentBuilder.newDocument();
		org.w3c.dom.Element root = document.createElement("xml");
		document.appendChild(root);
		for (String key : data.keySet()) {
			String value = data.get(key);
			if (value == null) {
				value = "";
			}
			value = value.trim();
			org.w3c.dom.Element filed = document.createElement(key);
			filed.appendChild(document.createTextNode(value));
			root.appendChild(filed);
		}
		TransformerFactory tf = TransformerFactory.newInstance();
		Transformer transformer = tf.newTransformer();
		DOMSource source = new DOMSource(document);
		transformer.setOutputProperty(OutputKeys.ENCODING, "UTF-8");
		transformer.setOutputProperty(OutputKeys.INDENT, "yes");
		StringWriter writer = new StringWriter();
		StreamResult result = new StreamResult(writer);
		transformer.transform(source, result);
		String output = writer.getBuffer().toString(); //.replaceAll("\n|\r", "");
		try {
			writer.close();
		} catch (Exception ex) {
		}
		return output;
	}


	/**
	 * 生成微信支付sign
	 */
	public static String createSign(SortedMap<String, String> params, String key) {
		StringBuilder sb = new StringBuilder();
		Set<Map.Entry<String, String>> es = params.entrySet();
		Iterator<Map.Entry<String, String>> it = es.iterator();

		//生成 stringA="appid=wxd930ea5d5a258f4f&body=test&device_info=1000&mch_id=10000100&nonce_str=ibuaiVcKdpRxkhJA";
		while (it.hasNext()) {
			Map.Entry<String, String> entry = (Map.Entry<String, String>) it.next();
			String k = (String) entry.getKey();
			String v = (String) entry.getValue();
			if (null != v && !"".equals(v) && !"sign".equals(k) && !"key".equals(k)) {
				sb.append(k + "=" + v + "&");
			}
		}

		sb.append("key=").append(key);
		String sign = CommonUtils.MD5(sb.toString()).toUpperCase();
		return sign;
	}


	/**
	 * 校验签名
	 */
	public static boolean isCorrectSign(SortedMap<String, String> params, String key) {
		String sign = createSign(params, key);
		String weixinPaySign = params.get("sign").toUpperCase();
		return weixinPaySign.equals(sign);
	}

	/**
	 * Map转有序Map
	 */
	public static SortedMap<String,String> mapToSortMap(Map<String,String> map){
		SortedMap<String, String> sortedMap = new TreeMap<>();
		for (String key : map.keySet()) {
			String value = map.get(key);
			String temp = "";
			if (null != value) {
				temp = value.trim();
			}
			sortedMap.put(key, temp);
		}
		return sortedMap;
	}

}
